Visual efficiency detection index : a new composite measure of visual search

Visual search is an important component of our interaction with our surroundings, allowing us to successfully identify external cues that impact our spatial navigation. Previous research has established fixation duration, fixation count, saccade velocity, and saccade amplitude as important indices of visual search. We examined the Visual Efficiency Detection Index (VEDI) comprising multiple aspects of visual search performance into a single measure of global visual performance. Forty participants, 10 adults ages 22-48, and children ages 6, 8, and 10, completed tests of working memory and visual search in response to stimuli relevant to pedestrian decision making. Results indicated VEDI statistically relates to established indices of visual search in relation to their interpretability for human performance. The VEDI was also sensitive to developmental differences in visual search performance, suggesting insight to its utility in the developmental psychological literature.

Hemispheric asymmetries in recognition memory for negative and neutral words

Federmeier and Benjamin (2005) have suggested that semantic encoding for verbal information in the right hemisphere can be more effective when memory demands are higher. However, other studies (Kanske & Kotz, 2007) also suggest that visual word recognition differ in function of emotional valence. In this context, the present study was designed to evaluate the effects of retention level upon recognition memory processes for negative and neutral words. Sample consisted of 15 right-handed undergraduate portuguese students with normal or corrected to normal vision. Portuguese concrete negative and neutral words were selected in accordance to known linguistic capabilities of the right hemisphere. The participants were submitted to a visual half-field word presentation using a continuous recognition memory paradigm. Eye movements were continuously monitored with a Tobii T60 eye-tracker that showed no significant differences in fixations to negative and neutral words. Reaction times in word recognition suggest an overall advantage of negative words in comparison to the neutral words. Further analysis showed faster responses for negative words than for neutral words when were recognised at longer retention intervals for left-hemisphere encoding. Electrophysiological data through event related potentials revealed larger P2 amplitude over centro-posterior electrode sites for words studied in the left hemifield suggesting a priming effect for right-hemisphere encoding. Overall data suggest different hemispheric memory strategies for the semantic encoding of negative and neutral words.

Memory and power : two movements

The institutions that work with the preservation and diffusion of cultural heritage - be them archive, libraries, museums, art galleries or cultural centres - present a certain discourse about reality. To understand this discourse, composed by sound and silence, by fullness and emptiness, by presence and absence, by remembrance and forgetting, an operation is implied, not only with the enunciation of speech and its gaps, but also the comprehension of that which causes to speak, of who is speaking and of the point whence one speaks. Preservation and destruction, or, in another way, conservation and loss, walk hand in hand in the arteries of life. As suggested by Nietzsche (1999, p.273), it is impossible to live without loss, it is entirely impossible to live avoiding destruction to play its game and drive the dynamics of life on. However, by means of a kind of tautological argument, one often justifies preservation by the imminence of loss and memory by the threat of forgetting. Thus, one ceases to consider that the game and the rules of the game between forgetting and memory are not fed by themselves and that preservation and destruction are not opposed in a deadly duel, but instead they complement one another and are always at the service of subjects that build themselves and are built through social practices. To indicate that memories and forgettings can be sown and cultivated corroborates the importance of working towards the denaturalisation of these concepts and towards the understanding that they result from a construction process also involving other forces, such as: power. Power is a sower, a promoter of memories and forgettings.